New Chinese model test.

Prompt:

Create a MIDI generator vst3 plugin based on picture. Plugin should first ask user to upload picture. Then there should be selector to choose the scale. It should include all most common scales, jazz and blues scale as well as major minor pentatonic scale and all modes (Dorian Lydian Mixolydian etc. ) then it should scan the image and create harmony and melody out of the image. It should scan mage in spiral from the center. Each pixel group (4×4) should translate to chord and melody in simple way. Chords should be sticky and persist for at least 4 pixel groups. Rhythm should be created from bottom 4 pixels. Chord should be done from two rows and melody from top row. Chords should be diatonic.
Use JUCE and c++ to create vst3 plugin working with DAWs on windows Mac and Linux.

Response:

Step-by-Step Explanation:

1. Set Up a JUCE C++ Project:

• Create a new JUCE project using the Projucer.
• Choose “MIDI Effect” or “Generic MIDI Plugin” as the plugin type.
• Ensure the project is configured for VST3 and targets Windows, Mac, and Linux.

1. Create the User Interface:

• Add a button for uploading an image.
• Implement a file chooser to select the image file.
• Add a dropdown or combobox for selecting the scale.
• Include options for all common scales, modes, jazz, and blues scales.

1. Implement Image Loading:

• Use JUCE’s File and Image classes to load and handle images.
• Read the selected image file and store it as a juce::Image object.

1. Implement Scale Selection:

• Create a list of available scales and modes.
• Map each scale to its corresponding notes.
• Allow the user to select a scale from the UI.

1. Spiral Traversal of the Image:

• Write a function to traverse the image pixels in a spiral order from the center.
• Determine the center coordinates based on the image dimensions.
• Collect pixels in 4×4 groups as specified.

1. Process Each 4×4 Pixel Group:

• For each group, extract the necessary pixels for chords and melody.
• Extract the bottom four pixels for rhythm information.
• Use two rows for chords and the top row for the melody.

1. Map Pixels to Musical Elements:

• Define a mapping from pixel values to musical notes.
• Ensure chords are diatonic to the selected scale.
• Implement “sticky” chords that last for at least four pixel groups.

1. Generate Rhythm from Bottom Pixels:

• Use the bottom four pixels to determine the rhythm pattern.
• Map pixel values to note lengths or velocities.

1. Output MIDI Data:

• Use JUCE’s MIDIOutput class to send MIDI events to the DAW.
• Schedule MIDI messages with appropriate timing based on the rhythm.

1. Handle MIDI Timing:
   • Synchronize MIDI output with the host DAW’s tempo.
   • Use JUCE’s MidiBuffer and timing functions for accurate scheduling.
2. Optimize Performance:
   • Optimize the spiral traversal and pixel processing for performance.
   • Consider multithreading if processing is too slow.
3. Test the Plugin:
   • Load the plugin into a DAW on different platforms.
   • Test with various images and scales to ensure correctness.
   • Debug any issues related to MIDI output or UI functionality.
4. Add Documentation and Error Handling:
   • Provide tooltips and instructions in the UI.
   • Handle cases where the image is not loaded properly.
   • Include logging for debugging purposes.

Sample Code Structure:// PluginProcessor.h class PluginProcessor : public juce::AudioProcessor #if JucePlugin_Type == juce::AudioPluginType::MidiEffect , public juce::MidiProcessor #endif { public: PluginProcessor(); ~PluginProcessor() override; void prepareToPlay(double sampleRate, int samplesPerBlock) override; void releaseResources() override; void processBlock(juce::MidiBuffer& midiMessages) override; juce::AudioProcessorEditor* createEditor() override; bool hasEditor() const override; voidgetStateInformation(juce::MemoryBlock& destData) override; void setStateInformation(const void* data, int sizeInBytes) override; // Image loading void loadImageFromFile(); // Scale selection void selectScale(int index); // Spiral traversal void traverseImageSpiral(); // Pixel group processing void processPixelGroup(const juce::Image& image, int x, int y); private: juce::File imageFile; juce::Image loadedImage; std::vector<std::string> scales; int selectedScaleIndex; // Add other necessary member variables }; // PluginEditor.h class PluginEditor : public juce::AudioProcessorEditor { public: PluginEditor(PluginProcessor& p); ~PluginEditor() override; void paint(juce::Graphics&) override; void resized() override; // UI components juce::TextButton loadImageButton; juce::ComboBox scaleSelector; // Add other UI components PluginProcessor& processor; private: void buttonClicked(juce::Button* button) override; void comboBoxChanged(juce::ComboBox* comboBox) override; // Add other UI callback functions }; // PluginProcessor.cpp PluginProcessor::PluginProcessor() : AudioProcessor(busesProperties), // Initialize member variables { // Initialize scales list scales = { "Major", "Minor", "Pentatonic Major", "Pentatonic Minor", "Dorian", "Lydian", "Mixolydian", "Jazz", "Blues" // Add more scales as needed }; selectedScaleIndex = 0; } void PluginProcessor::processBlock(juce::MidiBuffer& midiMessages) { // Implement MIDI processing logic // Use loadedImage and selectedScaleIndex to generate MIDI events } void PluginProcessor::loadImageFromFile() { // Implement file chooser and image loading juce::FileChooser chooser("Select an image file"); if (chooser.browseForFileToOpen()) { imageFile = chooser.getResult(); loadedImage = juce::ImageFileFormat::loadImage(imageFile); // Process the image as needed } } void PluginProcessor::selectScale(int index) { selectedScaleIndex = index; // Update scale-related parameters } // PluginEditor.cpp PluginEditor::PluginEditor(PluginProcessor& p) : AudioProcessorEditor(&p), processor(p) { // Initialize UI components loadImageButton.setClickingTogglesState(false); loadImageButton.addListener(this); addAndMakeVisible(&loadImageButton); scaleSelector.addItemList(processor.scales, 1); scaleSelector.addListener(this); addAndMakeVisible(&scaleSelector); // Set up UI layout setSize(400, 300); } void PluginEditor::buttonClicked(juce::Button* button) { if (button == &loadImageButton) { processor.loadImageFromFile(); } } void PluginEditor::comboBoxChanged(juce::ComboBox* comboBox) { if (comboBox == &scaleSelector) { processor.selectScale(comboBox->getSelectedIndex()); } }

Notes:

• Image Traversal:
• Implement a spiral traversal function that starts from the center of the image.
• Divide the image into 4×4 pixel groups and process each group sequentially.
• Mapping Pixels to Notes:
• Define a mapping function that converts pixel color values to MIDI notes.
• Ensure chords are diatonic by selecting notes from the chosen scale.
• MIDI Output:
• Use MIDIEventList or directly manipulate MidiBuffer to add events.
• Schedule notes with appropriate velocities and durations based on pixel data.
• Scale Implementation:
• Create a mapping from scale names to their note sequences.
• Generate chords and melodies based on the selected scale.
• Sticky Chords:
• Hold chords for multiple pixel groups to create sustained harmony.
• Use a counter to track how long a chord should be held.
• Rhythm from Pixels:
• Use the bottom four pixels of each group to determine rhythm.
• Map pixel brightness or color to note lengths (e.g., quarter, eighth notes).
• Performance Considerations:
• Optimize image processing and MIDI scheduling for real-time performance.
• Consider processing images in chunks or using background threads.
• Testing and Debugging:
• Test the plugin in a DAW to ensure MIDI output is correct.
• Use JUCE’s logging functions to debug issues.
• Cross-Platform Compatibility:
• Ensure the plugin compiles and runs on Windows, Mac, and Linux.
• Use JUCE’s cross-platform features to handle file paths and UI elements.

Conclusion:

By following these steps and implementing the provided code structure, you can create a VST3 MIDI generator plugin that translates images into music based on user-selected scales and image analysis. This plugin will offer a unique way for musicians and artists to create compositions from visual art.

Test result are promising. The task is very hard. LLM generated code which is compiling. The code is not complete but I did not expect it to be complete, it’s good starting point.

How o1 compares? More code, more explanations, still a skeleton but much more meat.

Below is a conceptual outline and example approach for building a JUCE-based VST3 plugin that generates MIDI from an image. This answer focuses on the key elements you will need: plugin structure (AudioProcessor / AudioProcessorEditor), file loading, scale/mode selection, the image-to-MIDI logic (spiral scanning, chord & melody generation), and basic chord/scale/mode handling.

This example is written in C++ and follows standard JUCE plugin conventions. It is not a complete, production-ready application; rather, it illustrates how one could structure and implement the requested functionality. You will still need to adapt it to your specific needs (e.g., adding user parameters, refining chord logic, properly scheduling MIDI events, customizing the GUI, etc.).

---

1. Overview of the Approach

1. Image Import + GUI:
   • Provide a “Load Image” button to allow the user to pick an image file.
   • Provide a combo box or similar control listing common scales/modes (major, minor, pentatonic, blues, Dorian, Lydian, Mixolydian, etc.).
2. Spiral Scanning:
   • Once the image is loaded, you’ll need to scan from the center in a spiral.
   • Extract 4×4 pixel blocks (16 pixels per step).
   • For each 16-pixel block:
   • Split them into logical groups:
     • Top row (melody generator).
     • Middle rows (chord generator).
     • Bottom row (rhythm generator).
3. Chord Generation (Diatonic “Sticky” chords):
   • Derive the chord from the middle rows of the 4×4 block.
   • Pick a chord based on pixel brightness or color mapped to scale degrees.
   • “Sticky” means the chord persists for at least 4 consecutive blocks (so you could store chord changes in a queue or only update chord every 4 blocks).
4. Melody Generation:
   • Top row determines melodic notes. Map these pixel values to scale intervals in the selected scale.
5. Rhythm Generation:
   • Bottom row (4 pixels) influences timing or velocity. For example:
   • If average brightness is high → shorter note length or higher velocity.
   • If average brightness is low → longer note length or lower velocity.
6. MIDI Event Scheduling:
   • In processBlock(), schedule note-ons and note-offs for chords and melodies to create a phrase.
   • You might render events one at a time or in small buffer blocks.
   • The simplest approach is to accumulate the entire “sequence” of chords & melodies offline (once the image is analyzed) and then step through it as the plugin plays.
7. Cross-Platform VST3 with JUCE:
   • JUCE supports building VST3 (as well as AU, AAX, etc.) for Windows, macOS, and Linux.
   • Ensure in Projucer that you have “Plugin is a Synth” enabled if you want to generate MIDI-only output (no audio processing).
   • In your processBlock, produce MIDI messages. If your DAW requires an audio channel, feed silent audio or bypassable audio as needed.

---

2. Example PluginProcessor.h

pragma once

include

// A simple struct to hold a single chord or melody event
struct MidiEventInfo
{
int midiNote;
float timePosition; // In beats or seconds, whichever is convenient
float duration; // How long the note should last
bool isChord; // Indicate if it belongs to chord or melody
};

class SpiralImageMidiGeneratorAudioProcessor : public juce::AudioProcessor
{
public:
//==============================================================================
SpiralImageMidiGeneratorAudioProcessor();
~SpiralImageMidiGeneratorAudioProcessor() override;// AudioProcessor overrides void prepareToPlay (double sampleRate, int samplesPerBlock) override; void releaseResources() override; bool isBusesLayoutSupported (const BusesLayout& layouts) const override; void processBlock (juce::AudioBuffer<float>&, juce::MidiBuffer&) override; //============================================================================== // Plugin internal parameters and logic void loadImage (const juce::File& imageFile); void setScale (const juce::String& scaleName); // Utility for spiral scanning void analyzeImageAndGenerateMidiSequence(); // Helper to retrieve MIDI sequence in real-time void renderNextBlockOfMidi (juce::MidiBuffer& midiMessages, int startSample, int numSamples); //============================================================================== // JUCE boilerplate juce::AudioProcessorEditor* createEditor() override; bool hasEditor() const override { return true; } const juce::String getName() const override { return ProjectInfo::projectName; } bool acceptsMidi() const override { return true; } bool producesMidi() const override { return true; } bool isMidiEffect() const override { return false; } double getTailLengthSeconds() const override { return 0.0; } // VST3 compatibility int getNumPrograms() override { return 1; } int getCurrentProgram() override { return 0; } void setCurrentProgram (int index) override { juce::ignoreUnused (index); } const juce::String getProgramName (int index) override { juce::ignoreUnused (index); return {}; } void changeProgramName (int index, const juce::String& newName) override { juce::ignoreUnused (index, newName); } void getStateInformation (juce::MemoryBlock& destData) override; void setStateInformation (const void* data, int sizeInBytes) override;

private:
// Your image:
juce::Image loadedImage;// The chosen scale or mode: juce::String currentScaleName { "C Major" }; // A container for the generated MIDI sequence: std::vector<MidiEventInfo> midiSequence; double currentSampleRate { 44100.0 }; // Current playback position in the pre-generated MIDI sequence size_t currentEventIndex { 0 }; float currentTimeInSamples { 0.0f }; JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (SpiralImageMidiGeneratorAudioProcessor)

};

---

3. Example PluginProcessor.cpp

include “PluginProcessor.h”

include

//==============================================================================
// Utility function to map pixel color/brightness to scale degrees.
static int getScaleDegreeFromPixelColor (juce::Colour c, int scaleSize)
{
// Simplistic approach: average RGB then map to a range [0, scaleSize-1]
auto brightness = (float)(c.getRed() + c.getGreen() + c.getBlue()) / 3.0f;
float normalized = brightness / 255.0f; // range [0..1]
int degree = (int) juce::roundToInt (normalized * (scaleSize – 1));
return juce::jlimit (0, scaleSize – 1, degree);
}

// A simple diatonic scale table (example for C major). You can customize or
// generalize to handle different roots and modes.
static const int cMajorScale[] = { 0, 2, 4, 5, 7, 9, 11 };
static const int cMinorScale[] = { 0, 2, 3, 5, 7, 8, 10 };
static const int cBluesScale[] = { 0, 3, 5, 6, 7, 10 };
// … define more scales / modes as needed …

// Convert scale degree to MIDI note. You should handle root note offsets
// (e.g. user picks “C# Dorian”), octave selection, etc.
static int convertScaleDegreeToMidi (int degree, const int* scale, int scaleLength, int rootNote = 60)
{
// We assume the degree is an index within the scale array
int steps = scale[degree % scaleLength];
int octaveOffset = (degree / scaleLength) * 12;
return rootNote + steps + octaveOffset;
}

//==============================================================================
SpiralImageMidiGeneratorAudioProcessor::SpiralImageMidiGeneratorAudioProcessor()
{
// Constructor
}
SpiralImageMidiGeneratorAudioProcessor::~SpiralImageMidiGeneratorAudioProcessor()
{
}

//==============================================================================
void SpiralImageMidiGeneratorAudioProcessor::prepareToPlay (double sampleRate, int samplesPerBlock)
{
currentSampleRate = sampleRate;
currentEventIndex = 0;
currentTimeInSamples = 0.0f;
}

void SpiralImageMidiGeneratorAudioProcessor::releaseResources()
{
}

bool SpiralImageMidiGeneratorAudioProcessor::isBusesLayoutSupported (const BusesLayout& layouts) const
{
// This plugin can be considered to have no main audio i/o if generating MIDI
return true;
}

// Main processing
void SpiralImageMidiGeneratorAudioProcessor::processBlock (juce::AudioBuffer& buffer,
juce::MidiBuffer& midiMessages)
{
// Clear the output buffer if needed
for (int channel = 0; channel < buffer.getNumChannels(); ++channel)
buffer.clear (channel, 0, buffer.getNumSamples());renderNextBlockOfMidi (midiMessages, 0, buffer.getNumSamples());

}

void SpiralImageMidiGeneratorAudioProcessor::loadImage (const juce::File& imageFile)
{
loadedImage = juce::ImageFileFormat::loadFrom (imageFile);
if (loadedImage.isValid())
{
analyzeImageAndGenerateMidiSequence();
}
}

void SpiralImageMidiGeneratorAudioProcessor::setScale (const juce::String& scaleName)
{
currentScaleName = scaleName;
// Potentially re-generate if user changes scale on the fly
if (loadedImage.isValid())
analyzeImageAndGenerateMidiSequence();
}

void SpiralImageMidiGeneratorAudioProcessor::analyzeImageAndGenerateMidiSequence()
{
// Clear any previous sequence
midiSequence.clear();
currentEventIndex = 0;if (! loadedImage.isValid()) return; int width = loadedImage.getWidth(); int height = loadedImage.getHeight(); if (width < 4 || height < 4) return; // 1) Compute the spiral order of 4x4 blocks from the center of the image. // We'll gather the blocks first, then process each block into chord & melody. // Center: int centerX = width / 2; int centerY = height / 2; // We’ll do a simplified “spiral” approach—expanding radius outwards // while going around in a square spiral pattern. // For each block, we define top row, middle rows, bottom row. // A small helper lambda to clamp x, y within the image: auto clampCoord = [&](int x, int maxX) { return juce::jlimit (0, maxX - 1, x); }; // Spiral iteration parameters int maxRadius = std::max (width, height) / 2; int dx = 0, dy = -1; int x = 0, y = 0; for (int r = 1; r < 2 * maxRadius; ++r) { // Move in spiral if ((-r/2 <= x) && (x <= r/2) && (-r/2 <= y) && (y <= r/2)) { int blockX = centerX + x * 4; int blockY = centerY + y * 4; // Now we have a top-left of the 4x4 block (roughly). // Check boundaries blockX = clampCoord (blockX, width); blockY = clampCoord (blockY, height); // Gather the 4x4 block’s colours, also checking boundaries juce::Array<juce::Colour> blockPixels; blockPixels.ensureStorageAllocated (16); for (int row = 0; row < 4; ++row) { for (int col = 0; col < 4; ++col) { int px = clampCoord (blockX + col, width); int py = clampCoord (blockY + row, height); blockPixels.add (loadedImage.getPixelAt (px, py)); } } // 2) Convert block to chord/melody/rhythm. // A real implementation might apply more sophisticated mapping. // Sticky chord logic: only update chord every 4 blocks static int blockCounterForChord = 0; static int currentChordRootDegree = 0; int chordRoot = currentChordRootDegree; int topRowDegrees[4]; int chordRowDegrees[8]; int bottomRowPixels[4]; // Example: top row = indices [0..3] in blockPixels // Middle rows = [4..11], bottom row = [12..15]. // However, be mindful that row major indexing in a 4×4 block is: // Row 0: indices 0..3 // Row 1: indices 4..7 // Row 2: indices 8..11 // Row 3: indices 12..15 // Top row → melody for (int i = 0; i < 4; ++i) topRowDegrees[i] = getScaleDegreeFromPixelColor (blockPixels[i], 7); // Middle rows → chord // indices: row1: [4..7], row2: [8..11] for (int i = 4; i < 12; ++i) { int localIdx = i - 4; chordRowDegrees[localIdx] = getScaleDegreeFromPixelColor (blockPixels[i], 7); } // Bottom row → rhythm for (int i = 12; i < 16; ++i) bottomRowPixels[i - 12] = (blockPixels[i].getRed() + blockPixels[i].getGreen() + blockPixels[i].getBlue()) / 3; // Use the 8 middle-row degrees to pick a chord root, e.g. average them float chordAverage = 0.0f; for (int i = 0; i < 8; ++i) chordAverage += chordRowDegrees[i]; chordAverage /= 8.0f; int blockChordDegree = (int)juce::roundToInt (chordAverage); if (blockCounterForChord == 0) currentChordRootDegree = blockChordDegree; blockCounterForChord = (blockCounterForChord + 1) % 4; // sticky for 4 blocks // 3) Build MIDI events // For simplicity, let's pick a chord by stacking triad in the scale: // root -> root + 2 -> root + 4 (within the scale degrees) // The actual scale used depends on currentScaleName. For example, cMajorScale. const int* theScale = cMajorScale; // Default int scaleLen = 7; if (currentScaleName == "C Minor") { theScale = cMinorScale; scaleLen = 7; } else if (currentScaleName == "C Blues") { theScale = cBluesScale; scaleLen = 6; } // ... handle other scale strings, or parse them more dynamically ... // Chord triad int chordRootNote = convertScaleDegreeToMidi (currentChordRootDegree, theScale, scaleLen, 60); int chordThirdNote = convertScaleDegreeToMidi (currentChordRootDegree + 2, theScale, scaleLen, 60); int chordFifthNote = convertScaleDegreeToMidi (currentChordRootDegree + 4, theScale, scaleLen, 60); // Rhythm from bottom row: // For instance, average brightness of bottom row might define note length or velocity float bottomAvg = 0.0f; for (int i = 0; i < 4; ++i) bottomAvg += (float) bottomRowPixels[i]; bottomAvg /= 4.0f; float velocity = juce::jmap (bottomAvg, 0.0f, 255.0f, 0.2f, 1.0f); float duration = juce::jmap (bottomAvg, 0.0f, 255.0f, 0.25f, 0.05f); // shorter vs longer // For each 4×4 block, let’s schedule a single chord + 4 notes in a small time region // In a real plugin, you’d map “timePosition” to beats or maybe just sequential blocks. float timeStart = (float) midiSequence.size(); // crude measure: 1 block = 1 “beat” or step // Add chord MidiEventInfo chordOnRoot { chordRootNote, timeStart, duration, true }; MidiEventInfo chordOnThird { chordThirdNote, timeStart, duration, true }; MidiEventInfo chordOnFifth { chordFifthNote, timeStart, duration, true }; midiSequence.push_back (chordOnRoot); midiSequence.push_back (chordOnThird); midiSequence.push_back (chordOnFifth); // Add melody notes from top row for (int i = 0; i < 4; ++i) { int noteDegree = topRowDegrees[i]; int midiNoteVal = convertScaleDegreeToMidi (noteDegree, theScale, scaleLen, 72); // maybe 1 octave up MidiEventInfo noteEvent { midiNoteVal, timeStart + (float)i * 0.1f, duration, false }; midiSequence.push_back (noteEvent); } } // Typical spiral stepping logic if (x == y || (x < 0 && x == -y) || (x > 0 && x == 1-y)) { int tmp = dx; dx = -dy; dy = tmp; } x += dx; y += dy; }

}

void SpiralImageMidiGeneratorAudioProcessor::renderNextBlockOfMidi (juce::MidiBuffer& midiMessages,
int startSample,
int numSamples)
{
// Accumulate MIDI messages from midiSequence.
// The simplest approach:
// 1 block in the sequence = 1 second (or some fraction).
// Convert timePosition to sample positions.float samplesPerSecond = (float) currentSampleRate; float endSample = currentTimeInSamples + (float) numSamples; // We’ll scan through midiSequence from currentEventIndex. for (; currentEventIndex < midiSequence.size(); ++currentEventIndex) { auto& eventInfo = midiSequence[currentEventIndex]; float eventSampleTime = eventInfo.timePosition * samplesPerSecond; // simplistic mapping if (eventSampleTime >= endSample) break; if (eventSampleTime >= currentTimeInSamples) { int samplePos = (int) (eventSampleTime - currentTimeInSamples) + startSample; // Make a noteOn juce::MidiMessage mOn (juce::MidiMessage::noteOn (1, eventInfo.midiNote, (juce::uint8) 100)); midiMessages.addEvent (mOn, samplePos); // Schedule noteOff in the future float noteOffTime = eventInfo.duration * samplesPerSecond + eventSampleTime; int noteOffSamplePos = (int) (noteOffTime - currentTimeInSamples) + startSample; juce::MidiMessage mOff (juce::MidiMessage::noteOff (1, eventInfo.midiNote)); midiMessages.addEvent (mOff, noteOffSamplePos); } } currentTimeInSamples = endSample;

}

//==============================================================================
juce::AudioProcessorEditor* SpiralImageMidiGeneratorAudioProcessor::createEditor()
{
// Return an instance of your custom Editor class
return new juce::GenericAudioProcessorEditor (*this);
}

// State management
void SpiralImageMidiGeneratorAudioProcessor::getStateInformation (juce::MemoryBlock& destData)
{
// Save parameters / scale name / etc.
juce::MemoryOutputStream stream(destData, true);
stream.writeString (currentScaleName);
}

void SpiralImageMidiGeneratorAudioProcessor::setStateInformation (const void* data, int sizeInBytes)
{
// Load parameters / scale name / etc.
juce::MemoryInputStream stream(data, static_cast (sizeInBytes), false);
currentScaleName = stream.readString();
}

---

4. Example GUI (simplified GenericAudioProcessorEditor or custom)

Below is a quick example using a basic AudioProcessorEditor with a file chooser and a combo box. In practice, you’ll create a more sophisticated editor.

Example PluginEditor.h:

pragma once

include

include “PluginProcessor.h”

class SpiralImageMidiGeneratorEditor : public juce::AudioProcessorEditor,
private juce::Button::Listener,
private juce::ComboBox::Listener
{
public:
SpiralImageMidiGeneratorEditor (SpiralImageMidiGeneratorAudioProcessor&);
~SpiralImageMidiGeneratorEditor() override;void paint (juce::Graphics&) override; void resized() override;

private:
void buttonClicked (juce::Button* button) override;
void comboBoxChanged (juce::ComboBox* comboBoxThatHasChanged) override;SpiralImageMidiGeneratorAudioProcessor& audioProcessor; // GUI components juce::TextButton loadImageButton { "Load Image" }; juce::ComboBox scaleComboBox; JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (SpiralImageMidiGeneratorEditor)

};

---

Example PluginEditor.cpp:

include “PluginEditor.h”

SpiralImageMidiGeneratorEditor::SpiralImageMidiGeneratorEditor (SpiralImageMidiGeneratorAudioProcessor& p)
: AudioProcessorEditor (&p), audioProcessor (p)
{
setSize (400, 300);addAndMakeVisible (loadImageButton); loadImageButton.addListener (this); // Populate scales scaleComboBox.addItem ("C Major", 1); scaleComboBox.addItem ("C Minor", 2); scaleComboBox.addItem ("C Blues", 3); // ... add more modes/scales as needed ... scaleComboBox.setSelectedId (1); addAndMakeVisible (scaleComboBox); scaleComboBox.addListener (this);

}

SpiralImageMidiGeneratorEditor::~SpiralImageMidiGeneratorEditor()
{
loadImageButton.removeListener (this);
scaleComboBox.removeListener (this);
}

void SpiralImageMidiGeneratorEditor::paint (juce::Graphics& g)
{
g.fillAll (juce::Colours::black);
g.setColour (juce::Colours::white);
g.drawFittedText (“Spiral MIDI Image Generator”, getLocalBounds(), juce::Justification::centredTop, 1);
}

void SpiralImageMidiGeneratorEditor::resized()
{
loadImageButton.setBounds (10, 40, getWidth() – 20, 30);
scaleComboBox.setBounds (10, 80, getWidth() – 20, 30);
}

void SpiralImageMidiGeneratorEditor::buttonClicked (juce::Button* button)
{
if (button == &loadImageButton)
{
// Show a file chooser
juce::FileChooser chooser (“Select an image to load…”, {}, “.jpg;.png;*.jpeg”);
if (chooser.browseForFileToOpen())
{
auto file = chooser.getResult();
audioProcessor.loadImage (file);
}
}
}

void SpiralImageMidiGeneratorEditor::comboBoxChanged (juce::ComboBox* comboBoxThatHasChanged)
{
if (comboBoxThatHasChanged == &scaleComboBox)
{
auto selectedId = scaleComboBox.getSelectedId();
switch (selectedId)
{
case 1: audioProcessor.setScale (“C Major”); break;
case 2: audioProcessor.setScale (“C Minor”); break;
case 3: audioProcessor.setScale (“C Blues”); break;
default: audioProcessor.setScale (“C Major”); break;
}
}
}

---

5. Key Points & Next Steps

• The above code outlines how to:
  1) Load an image.
  2) Spiral-scan it in increments of 4×4 blocks.
  3) Map pixel data to chords (middle rows), melody (top row), and rhythms (bottom row).
  4) Convert those into scheduled MIDI events (note on/off).
  5) Render them in processBlock.
• To refine chord logic, consider:
  – Distinguish chord types (major, minor, seventh, etc.).
  – Make chord changes more musical by analyzing the average of multiple blocks or randomizing lightly.
• Scale & Mode selection:
  – You can store a map or function that returns the scale array & length for any scale name (e.g. D Dorian → root = D, pattern = {0, 2, 3, 5, 7, 9, 10}, etc.).
  – Make sure you handle transposition if the user picks a root note other than C.
• Rhythm:
  – You can expand the bottom row logic so that each pixel generates a different velocity or length for each quarter within the block time.
  – If you want a true sense of tempo, you need to map your durations to beat units (quarter notes, eighth notes) at a specific BPM, rather than raw “1 block = 1 second.”
• GUI:
  – Replace the GenericAudioProcessorEditor with a custom editor for a polished look.
  – Display the loaded image if desired, highlight the scanning spiral, etc.
• Platform Builds:
  – Use Projucer’s exporter settings to build VST3 for Windows, macOS, and Linux.
  – Make sure to enable “Plugin is a Synth” so the DAW routes MIDI properly.

This skeleton should give you a solid foundation to continue developing a MIDI generator plugin that reads an image, scans it in a spiral, and emits chords and melodies based on a selected scale and the 4×4 block logic. You will eventually refine the data mappings, chord longevity (“sticky” chords), and ensure a smooth, musically coherent output.